This invention relates to a positionable transducer and particularly to the structural frame for maintaining the transducer in an orthogonal relationship with respect to an elongated track upon a record medium surface such as video tape.
U.S. Pat. No. 4,093,885 granted to David E. Brown, June 6, 1978 and assigned to Ampex Corporation describes a TRANSDUCER ASSEMBLY VIBRATION SENSOR used to read and record with respect to a videotape helically wrapped on a drum as shown in Prior Art FIGS. 15 and 16. The problem with the Brown mounting structure was the fact that as the cantilevered positioning element or driver deflected, the transducer at the free end of the cantilever tilted at an angle with respect to the video tape. The amount of inclination varied proportionately to the amount of deflection of the positioning element. Since electrical signal degradation is logarithmic relative to inclination, it is extremely important to maintain the transducer in orthogonal relationship to the video tape.
Hathaway, U.S. Pat. No. 4,099,211 granted July 4, 1978 and assigned to Ampex Corporation, teaches a POSITIONABLE TRANSDUCING MOUNTING STRUCTURE AND DRIVING SYSTEM THEREFOR. The Hathaway positioning means discloses a complex method of dividing the positioning member which is more specifically a piezoelectric ceramic bender element, into two physically distinct members and two separate electrically isolated elements. The separate elements are oppositely electrically charged to cause them to bend in opposite directions as the divided positioning element deflects. The voltage must be carefully regulated to cause the correct degree of bending as the deflection increases. Hathaway also recognized that his positioning element had a tendency to twist and he therefore divided his positioning member longitudinally into two electrically isolated elements so that oppositely charged driving voltage could be applied to cause the elements to bend in opposite directions.